Burglar-alarm



2' SheetsSheet 1.

E. BROWN. Tm Alarm;

Patehted Oct. 31, 1854.

UNITED STATES PATENT OFFICE.

EPHRAIM BROWN, OF LOWELL, MASSACHUSETTS.

BURGLAR-ALARM.

Specification forming part of Letters Patent No. 11,856, dated October31, 1854; Reissued March 6, 1860, No. 924.

T 0 all whom it may concern Be it known that I, EPHRAIM BROWN, ofLowell, in the county of Middlesex and State of Massachusetts, haveinvented a new and useful Thief Detector or Alarm Apparatus to beApplied to Money-Drawers in Order to Give Notice when Any ImproperAttempt is Made to Open the Same; and I do hereby declare that the sameis fully described and represented in the following specification andthe accompanying drawings, letters, figures, and references thereof.

Of the said drawings, Figure 1 denotes a top View of a drawer with mysaid invention applied to it. Fig. 2 is a sectional view of the drawerand made to show a side elevation of the mechanism contained therein,the side plate of the case of said mechanism being removed in order tomore clearly exhibit the parts in rear of it. Fig. 3, is a vertical andtransverse section of the drawer, such section being taken in front ofthe two keys to be hereinafter described, or between them and the knoband so as to exhibit them and the counter mechanism. Fig. 4, is anothersuch section taken just in front of the alarm mechanism.

In the said drawings A denotes the drawer, of which 13 is the knob bywhich said drawer is usually operated or pulled outward. C denotes thecounter or board under which the drawer is placed and made to slide inand out-on rails D, D. Throughout the middle of this drawer, in case asingle knob is used on it, I arrange the case of alarm apparatus ordetector as seen at E, placing at the rear end of this case and withinthe drawer a bell F. In front of the bell and within the case is placedan alarm striking apparatus as seen at G. The hammer. of this alarm isshown at H, such alarm apparatus being of the kind commonly sold in themarket and applied to clocks for the purpose of converting them intoalarm clocks.

A top View of the alarm apparatus I have given in Fig. 5, and a centraland longitudinal section of it in Fig. 6.

As it is an apparatus that is well known to all clock makers it willonly be necessary for me briefly to describe its principal parts. Itconsists of a driving or key shaft a, to which and the case b, a coiledor spiral spring 0, is adapted so as to rotate the shaft in a directionopposite to that in which said spring may be wound up. d, is a key wheelplaying loosely upon the wheel shaft. a ratchet fixed upon the key shaftand working against a spring pawl f, adapted to the side of the gear.The said gear plays in a lantern pinion g, fixed upon another shaft h,carrying an escapement wheel 2'. To this escapement wheel the hammer ofthe bell is connected by an escapement is. \Vhen the main spring iswound up and set free it will so set in operation the mechanism as tocause a constant succession of blows of the striking hammer upon thebell E, to take place.

There projects from the inner side of the escapement wheel a pin or stopZ, which operates in connection with an alarm pawl m, that extends alongunderneath the key shaft and jointed at its front or lower end to amovable hanging lever n, which plays or oscillates on a pin 0, andbetween two stop studs 79, When this hanging lever is drawn in adirection toward the knob it will cause the alarm pawl to be drawn fromunderneath the stud or pin of the escapement wheel so as to permit thesaid escapement to revolve. The return movement of the hanging leverforces the alarm pawl in the path of rotation of the said stud or pin,and when said stud or pin strikes upon the pawl its fiurther rotationwill be arrested by said paw A spring r, is applied to the hanging leverto force it in a direction toward the alarm apparatus. Through saidhanging lever a long rod .9, is made to slide, such rod at its front endbeing attached to the knob which is made to slide freely in an axialdirection in a passage or opening t, formed in the front board of thedrawer. This rod presses against the shorter vertical arm of a bentlever u, that plays upon a fulcrum o, and has its longer arm jointed toa vertical latch or spring bolt arranged as seen in the drawings andmade to operate in connection with an inclined catch a: fixed underneaththe counter boards as seen in the drawings. \Vhen the knob is pressedinward the spring bolt will be forced downward.

A locking bolt or cone is applied to the latch bolt; it extends andslides through the latch bolt and passes into the end part, b, of thecase. While it is in said part, I), the bolt is prevented by it frombeing depressed or is locked in position; but when it is drawn out ofthe said part, b, the bolt is set free eis so that it may be moveddownward by pressing the lamb inward. This locking bolt or cone isjointed to a key lever, d, which plays upon a stationary pin or fulcrum,f, and has its tail arm extended through the bottom of the drawer. Thereis also another such lever placed upon the said pin as seen at g. Thislatter lever is so connected to the hanging lever before mentioned bymeans of draft rods, h, i, that any movement of the lever eitherbackward or forward shall cause the hanging lever to be drawn toward theknob and so as to cause an alarm to be sounded.

The hanging lever is also connected with the first key lever by means ofa connecting rod, 6, and so that said. hanging lever may be drawn towardthe knob whenever the lower arm of the key lever is pulled toward thesame. The hanging lever carries an impel ling pawl, Z, which worksagainst a ratchet, n, fixed upon a horizontal shaft, 0, made to carry aregistering or counter wheel 39, whose circumference is divided into thesame number of parts that there are in the ratchet Wheel, the partsbeing designated by the figures l, 2,3,4,&c. Directly over this wheelthere is a slot or orifice 9 made through the top-plate of the case ofthe alarm apparatus, and so as to have a width corresponding to one ofthe divisions of the counter wheel. The objectof this counter wheel isto enable a person to ascertain at any time what number of attempts mayhave been made to open the drawer, as the counter wheel will be movedone division whenever either of the lower arms of the key lever aremoved so as to cause an alarm to be sounded. It will also be moved onedivision whenever the knob is moved so as to sound an alarm. I

Whenadrawer is fitted up with a thief detector of the above description,and the main spring alarm apparatus is wound up, the drawer beingsupposed to be locked by the spring bolt, the natural method by which aperson, who did not know that the drawer had an alarm apparatus appliedto it, would attempt toopen the drawer would be, to seize upon the knoband pull it toward him;

. when this is done, it will readily be seen, not

only that the drawer cannot be opened but that an alarm will be sounded.

In order to open the drawer aperson must press inward the knob with thethumb extending the fingers of the hand under the drawer and againstthat part of the back side of the front board of it which projects thehanging lever for the purpose of deceiving a thief or person notacquainted with the mechanism. Whenever it is moved it will cause analarm to be sounded.

hat I claim as my invention isv 1. The making of the knob of a drawermovable, and so combining it with an alarm apparatus as to causean alarmto be sounded whenever an attempt to open the drawer by pulling on theknob is attempted.

2. I also claim the combination of the latch or spring bolt and thesecondary bolt and key or lever with the movable knob and the drawer thesame being to operate together asspecified. I y

3. I also claim the combining of the alarm pawl m, with the knob rod bymeans of a movable hanging lever, 11-, to be operated'or moved bya, studor its equivalent fixed to the knob rod.

at. I also claim the decoy key and its connections with the hanginglever so as to 0p erate as specified; also the connect-ing the saidhanging lever to the secondary lever, so

that a forward pull on the secondary lever shall move the hanging leverso as to eifect the sounding of the alarm.

5. I also claim the .combination of the counter or number and itsoperative mech-' EPHRAIM BROWN.

Witnesses J AS. DINsMooR, JOHN B. MARSHALL.

[FIRST PRINTED 1913.]

